Fuel burning method and apparatus



May 2, 196] Filed Jan. '7, 1957 gag J. H. KIDWELL ET AL FUEL BURNINGMETHOD AND APPARATUS FIG. 1

2 Sheets-Sheet 1 INVENTORS John H. Kidwell Gveor e MusaT .MarquandATTORNEY May 2, 1961 Filed Jan. 7, 1957 J. H. KIDWELL ETAL FUEL BURNINGMETHOD AND APPARATUS ATTORNEY 2 Sheets-Sheet 2 INVENTORS John H. KidwellGeorge Musaf United States Patent P 2,982,347 FUEL BURNING METHOD ANDAPPARATUS John H. Kidwell and George Musat, Canton, Ohio, and Kenneth E.Marquand, Denver, Colo., assignors to The Babcock 8: Wilcox Company, NewYork, N.Y., a corporation of New Jersey Filed Jan. 7, 1957, Ser. No.632,884

10 Claims. (Cl. 158-11) This invention relates to a fuel burningapparatus and method and more particularly to an improved fluid fuelburning method and apparatus forbnrning either a liquid or gaseous fuel,separately or in combination.

In relatively large gas and/or liquidfuel fired vapor generating units,it is customary to fire the same by a plurality of burners adaptable forburning either gas or liquid fuel, such as oil, separately or incombination depending on the amount and kind of fuel available.Heretofore, the standard type of burner in use on a large generatingunit, whether fired by either oil or gas or in combination, had anindividual maximum load capacity of approximately 70 to 90 millionB.t.u.s per hour and required various adjustments of air register doorsand distance piece to establish desired intermediate burner loadconditions between the minimum and maximum burner capacities. Theseburners further utilized a vaned throat piece or other mechanical meansto facilitate mixing of the air with fuel and an impeller means toretain the flame at the burner tip when oil was fired, the impellerbeing removable in the case of a multiple fuel burner when gas wasburned. I

In recent years the trend has been toward larger vapor generating units.As the standard type of fuel burners had limited maximum load capacitiesdue to the inherent construction characteristics thereof, the trend tolarger vapor generating units necessitated a steady increase in thenumber of burners provided for each unit. In some instances, the numberof burners on a single unit has reached as high as 32. Such amultiplicity of burners greatly complicated the construction of theboiler walls as well as the windbox. The excessive number of burnersfurther increased the burner air distribution problem and the burnercontrol problem especially when remote burner light-off and individualflame failure protection was required. Furthermore, the constant andperiodic replacement of impeller means which constantly burned outfurther increased the maintenance and operating cost of the impellertype burners heretofore known.

An object of the present invention is to provide an improved fuel burnercapable of having a substantiallygreater maximum load capacity so thatthe number of burners required for the larger present-day vaporgenerating'units can be kept to a minimum, thereby greatly reducing thedifliculties and complexities of the furnace wall construction as wellas the operation and control of the burners.

Another object of this invention is to provide animproved fuel burnerwhereby suflicient combustion air is directed to the central portion ofa burner throat so that the performance characteristics of the burnerare such that no impeller is necessary and which requires only a singlesetting of the air doors and distance piece throughout the entireoperating range of the burner.

Still another object of the instant invention is to provide a novelmethod of burning a fluid fuel wherein the retention of the flameadjacent the tip of the burner is accomplished physically by means of apressure differential within the combustion air stream instead of amechanical means such as an impeller or the like. 7

Accordingly, the objects, features and advantages of the improved burnerof the instant invention are accomplished by a gas and/ or liquid fuelburner having an air register means spatially disposed from a burner orthroat opening located in a furnace wall by means of a conduit in whichthere is located along a longitudinal axis thereof a liquid fuelatomizer means. Disposed in spaced relationship within the conduit andabout the atomizing means is an inner sleeve havingan inlet and outletend, the inlet end thereof extending into the air register portion ofthe burner to divide the register air into an inner and outer airstream. In addition to dividing the air into a plurality of air streams,the sleeve positively directs a suflicient amount of turbulent air tothe central throat portion of the burner. Means are provided in the airregister portion for imparting relative velocities to the air streamswherein the inner air stream has imparted thereto a greater spinning orwhirling tangential velocity than that of the outer air stream whereby arelatively lower pressure zone is created at the outlet or centralportion of the burner tip. Consequently a highly turbulent air mass orstream is positively delivered to the central portion of the burnerwhere it is most desired and thoroughly mixed with the fuel injectedtherein to promote combustion, the highly turbulent air stream creatingthe lower pressure zone at the center portion of the burner to establisha flame holding condition thereat.

According to this invention if gas is the intended fuel to be burned,either separately or in combination, a plurality of elongated gas spudsare provided wherein the tip portions thereof are circumferentiallyspaced adjacent the outlet end of the inner sleeve, the spuds havinglongitudinally spaced along the axis thereof a plurality of gas orificesin addition to'orifice openings in the tip thereof for directing gasinto both the inner and outer air streams to facilitate the mixing ofthe gas with the air.

In accordance with this invention, the improved method of burning gas oroil either separately or in combination so as to substantially increasethe maximum load capacity of a burner is accomplished by supplyingcombustion air to an air register means wherein it is divided intot'aplurality of air streams, namely an inner and outer air stream havingrelative velocities, imparting the inner air stream with a whirlingvelocity greater than that of the outer air stream so as to create ahighly turbulent air mass and directing the highly turbulent mass of airto the central portion of an enlarged burner opening. Fuel is thenejected into the air stream adjacent the merging zone of the two airstreams whereby the fuel is thoroughly mixed therewith without furtheraids of any mechanical means, the relative velocities of the air streambeing further maintained so as to create relative pressure zones whichfurther enhances mixing as the air streams merge adjacent the fuelinjection portion of a burner, the relative velocities of said streamfacilitating a flame holding or stabilizing condition of the burner tip.

While the burner of the instant invention may be utilized separatelyeither asa gas burner or an oil burner, the concepts herein stated areequally well adapted for use in a combination gas and/or oil burnerwherein the operations, and novel principles and method of mixing thecombustion air with either of said fuels or combinations thereof remainsubstantially the same.

A feature of this invention resides .in the provision whereby thecapacity of the instant burner is substantially doubled that of thestandard type burner commonly used today, i.e., the improved burnerhaving a maximum capacity of to 183 million B.t.u./hour.

Another feature of this invention resides in the provision whereby twOpieces of control equipment, namely Patented May 2, 191 V the registerair door and impeller adjustments, are eliminated.

Still another feature of the invention resides in the provision wherebythe air register is removed from the heat radiation effects of thefurnace.

A further feature of this invention resides in the provision whereby asuflicient portion of the combustion air is positively directed to thecentral area of the burner throat to promote combustion thereat andthereby enabling the size of the burners to be efficiently increased.

Another feature of this invention resides in the provision whereby thesmaller diameter of the inner sleeve or inner annulus results in aninner air stream having high rate of spinning or angular velocityrelative to that of the outer air stream thereby creating a low pressurezone which acts as a pneumatic flame holder at the burner tip.

Still another feature of this invention resides in the provision wherebythe burner conduit is substantially equal to the diameter of the burnerthroat thereby eliminating the requirement for an entrance cone andvanes, impellers or the like to induce a whirling or spinning velocityto an air mass.

Still another feature of the invention resides in the provision wherebythe merger of the divided air mass at the burner tip produces anadditional turbulence beneficial to promoting combustion.

Other features and advantages will be readily apparent when consideredin view of the drawings and accompanying description in which:

Fig. l is an elevation view of the improved gas and oil burner havingparts thereof broken away and shown in section.

Fig. 2 is a front end view of the instant burner.

Fig. 3 is an elevation view of a modified burner having parts shown insection.

Fig. 4 is a front end view of the modifier burner having parts thereofshown in section.

In order to meet the capacity and operational demands of a modern steamgenerating unit or the like whereby the same is desired to be fired by aminimum number of fuel burners and whereby reduce the complexity of theboiler wall construction as well as the operation and control of theburners, there is shown in the drawings in accordance with thisinvention, an improved burner construction capable of a maximum loadcapacity which is substantially twice that of the standard 27" circularburner commonly used at the present time. The defined maximum operatingcapacity of the instant burner is rated at between 145 to 183 millionB.t.u.s per hour. while the instant burner construction is equallysuitable for independently burning different types of fuel, it is hereinillustrated and described for the purposes of description as acombination oil and gas burner which is adaptable for burning either oilor gas separately or in combination.

In the drawings, Figs. 1 and 2, reference numeral is directed to awater-cooled furnace front wall having a circular opening 11 in whichthe throat 12 of the burner is located. In accordance with thisinvention, the inner surface of the throat 12 diverges outwardly andtoward the furnace side of the wall, the angle of divergement being atleast 120 degrees. As it will be hereinafter explained, this wide anglethroat reduces fuel impingement thereat and resulting difficultiestherefrom at low loads and tends to produce a flow pattern of an orificehaving a vena contracta effect which promotes recirculation of the gasesand the unburned matter into the main body of the flame.

In the form of the invention illustrated by Figs. 1 and 2, there isspaced from the front wall 10 a casing 13 having an access opening 14closed by an annular closure plate 15, the space between the front wall10 and casing 13 forming a windbox or passageway in which combustion airis delivered from an air blower (not shown) to the burner. A circularclosure 16 having a laterally extending collar 17 projects through thecentral opening of the closure plate 15 covering the windbox accessopening 14.

As shown, the air register 18 is connected to collar 17 and comprises apair of spaced annular members 19, 20 forming the end walls thereof.Circumferentially spaced and pivotally mounted between and adjacent theouter periphery of the end Walls 19, 26 of the air register are aplurality of register doors 21 which are adapted to be pivoted betweenopen and closed positions and which in the open position enables the airregister to be in communication with the interior portion of thewindbox. If desired, the air doors 21 may be suitably geared, linked orotherwise connected together so as to be responsive to an operatingmeans which may be either manually or automatically controlled tosimultaneously operate the doors in response to the actuation of theoperating means. In the illustrated form of the invention, the operatingmeans comprises a manually operated means 22. Thus, it will be notedthat in the event that it is necessary to shut down the burner, all thedoors 21 may be simultaneously moved to closed position by operation ofmeans 22 to cut off the air supply to the burner. It will be noted alsothat the air doors 21 in addition to admitting air into the the airregister when in open position also imparts to the air enteringthereinto a whirling, spinning or angular velocity.

According to this invention, the air register 13 is laterally spacedfrom the burner throat 12 by a burner tube or conduit 23, the latterbeing substantially equal in diameter to the throat opening and disposedadjacent thereto, thereby eliminating the need of an entrance cone.Consequently, it will be noted that the register 18 is set back in thewindbox and remote from the radiation effect of the furnace.

Located centrally of the air register 18 and extending along thelongitudinal axis of the burner conduit 23, there is disposed a suitableoil atomizing means 24 having its rear portion supported in the circularclosure 16 and its forward end supported by a suitable bracket or spider25.

According to this invention, there is spatially disposed within theburner conduit 23 and about the fuel atomizing means 24 an inner sleevemember or annulus 26 having an inlet end 26A, and an outlet end 26B. Asshown in Figure 1, the inlet end 26A of the sleeve member 26 extendsinto the air register 18 and is flared outwardly or hell shaped todivide the register air into an inner air mass or stream and an outerair mass or stream. Bracket or struts 25A and 25B support the innersleeve in spatial relationship within burner conduit 23.

In the form of the invention shown in Figs. 1 and 2, it is to be notedthat the air entering the air register has imparted thereto an angularvelocity through doors 21 which is retained in the divided air streams,although it has been discovered that the angular velocity of the outerair stream is substantially reduced adjacent the discharge end of theburner. Since the diameter of the inner annulus or sleeve member 26 issmaller than that of the burner conduit 23, the inner core of air orstream flowing through the sleeve has imparted thereto a relativelygreater angular velocity than that of the outer air stream. As a resultof the increased angular velocity of the inner core, the central portionor mass of air is rendered highly turbulent, the turbulent mass of airbeing directed by means of the sleeve to the center portion of theburner throat. Since a sufficient amount of turbulent air can bepositively directed to the central portion of a burner in the mannerdescribed, the size of the burner may be efficiently increased. A burnerhaving a throat opening with a 36 inch diameter proved successful. As aresult of the diiferential of velocities established between the innerand outer air streams it will be noted that a lower pressure zone iscreated at the central portion of the burner. It has been discoveredthat the reduced pressure zone at the center of the burner,

1 together with the whirling effect of the inner air stream establisheda flame holding condition at the burner tip, thereby eliminating theneed for an impeller.

In order that the burner of Figs. 1 and 2 may also operate on gas, aplurality of gas spuds 27 are circumferentially spaced around andadjacent to the discharge end 2612 of the inner sleeve member 26. Asshown in Figs. 1, it has been discovered that the most effectivearrangement of the gas spuds 27 is to have the tip portion 27A thereofproject through the burner conduit 23 in the vicinity of the outlet end26B of the inner sleeve as shown. In this manner, the spuds 27 do notinterfere with the air flow through the burner.

In order to facilitate the removability or replacement of thegas spuds,it will be noted that the spuds com-.

prise an elongate tubular member 27B having an arcuate configuration ofa suflicient radius so that the same can be readily inserted through anopening in the circular closure plate 15, the arcua-te configuration ofthe spud 27 being such that the same clearsthe register portion 18 ofthe burner as it is inserted through the, opening 28 in the burnerconduit 26. In the form shown, twelve spuds 27 are equidistantly spacedaround the discharge end 263 of the burner tube 26, the end portionsthereof being connected to a gas ring manifold 29' adjacent the frontwall of the burner and the manifold 29' being connected to a source ofgas supply (not shown) by means of a supply pipe 29A.

In accordance with this invention, it will be noted that the tip 27A ofeach gas spud is provided with a plurality of spaced gas orifices 30'extending along the longitudinal:

axis thereof in addition to the plurality of gas orifice openings 31located in the tip portion of the spud. The

1 gas orifices 30 extending along the longitudinal axis of the spudarepositioned so as to direct a gas outwardly therefrom on both sidesthereof in a direction substantially 90 transverse to that of air streamflow. With able a suflicient amount of turbulent air at the centralportion of the burner so asto promote thorough mixing of thefuel'withthe air necessary for proper combustion.

Further, it is to be noted that the relative velocitiesim- .jflp'artedto the airstream create relative pressure zones with it he'lowerpressure zone formed at the center portion.

of the burner and functions as a pneumatic flame holder.

"The burner is alsoprovided'with an igniter means 32 and usualinspection door 33.

-The,burner 'is lighted by means of the igniter 32 V,

6 angled throat opening 51 located in a furnace wall 52 as 'hereinbeforedescribed. A burner conduit 53 extends forwardly of the burner opening,having an oil atomizing means 54 being located along the central axis-'thereof. Axially and spatially disposed within the burner conduit 53and about the atomizer means 54, there is provided an inner sleeve orannulus member 55 having an inlet end 55A extending beyond the inlet end53A of the burner conduit 53. As shown in Figs. 3 and 4,

the inlet end 55A of the inner sleeve 55 is provided with a pair ofspaced laterally extending flanges 55B, 55D having horizontally disposedth erebetween and circumferentially spaced thereabout a plurality ofvanes 56.

' A' casing'member 57' spatially surrounds the burnerconduit 53, thecasing 57 having a front wall 57A abutting the inlet end 55A of theinner sleeve. Thus an annular air chamber 58 is formed between thecasing 57 and conduit 53 which isin communication with an air duct 59connected to a header or source of combustion air (not shown),

As indicated by the arrows A, the combustion air enters the annular airchamber 58 and is directed to the forwardor air register portion 58A ofthecasing wherein the mass of combustion air is divided into an outerair stream having generally an axial velocity and an inner air streamflowing through the inner sleeve, member, the latter stream havingimparted thereto by the vanes 56 a highly turbulent angular and helicalvelocity.

Consequently as hereinbefore described, the relative velocities of theair stream creates a differential pressure zone within the burner toenhance the mixing of the air and fuel as well as to create a flameholding condition at the tip of the burner.

As shown in Fig. 3 damper means 60 are provided to-cut off the airsupply to the'burners, the damper means 60 being optionally disposed ateither in the-inlet air duct as shown or in the air chamber 58 adjacentthe air register portion 58A as shown in the phantom line.-

With this arrangement, it will be noted that the necessity of a largewindbox on a multiple burner generating unit can be eliminated and thatwith the modified burnor of Figs. 3 and 4 of a multiple'arrangement,each burner can be supplied through an individual inlet. This"arrangement permits individual adjustment of the burner control dampersto compensatefor unequal air distribution if such is necessary.

In the event that gasis to be fired, the modified burneris providedwith-a plurality of gas spuds 61 circumferentially spaced about outletend B of the inner sleeve 55 in the manner hereinbefore described, thegas spuds being connected to a-sui-table manifold 62. 'In all otherrespects, the operation and function of the modified burner issubstantially the same as the'burner illustrated in Figs. 1 and 2.

The method herein employed by which the maximum .capacity of to 183million B.t.u. is attainable by the burner construction herein shown anddescribed com prise the steps of introducing a supply of combustionairthe usual manner whether fired vongas or oil with the .air

doors wide open. With the burner in operation, the

firing rateflcan be varied overa '10 to 1 range from 1,090 to IlL OOGlbs. of oil without the requirement or any furthe'r adjustment of thedoor 21 or the distance .l piece of the fuel atomizing means Theflamehas a short, snappy well-defined patterniwith excellent staj'bility'andfcompleie"combustion is h'ad'over'ijthe entire; firing rangewithin the' "standardlimitation of excess air. i Furthergthe wide angle,burner throat discharge results U ina'p'ositive flame-pattern in themain flamejbody ands "alisoin the outer "frontal zohe where'lthe fiameis recircuj "lated to the rootofthe initial combustion zone,

"ofth'e instantinvention are such that theiimpeller 'andinherentdisadvantages ther'edf are eliminated; Also into an air registryportion 58A of a burner and divid ing the same into a plurality of airstreams namely aninner'a1rstream and' an outer air stream and imparting.to

the air streams arelativevelocity-. Accordingly, the in-- t ner airstreamv has imparted theretopahighly 'turbulent 7' tangential velocitygreater than that of the outer. air 7 stream the former being positivelydirected to the central portion of the burnerwhere itis needed most;This f v condition, 'it will-the noted," enhances 'thorough'mixing'ofj 1"fthe air and fuel whichisinjected'into theair streams. I i

- For the foregoing, it will be'noted that the novel burn er;constructionland method-ofburning enables the size v I o f the burner:to be efiiciently-incr eased whereby maxi- 1 .mum capacity'the'reof is,greatly increased.. Runthe that i i operating charaeterietics ofthe'illustrated embodi-i the operation and'control of the improved burnersof the instant invention are greatly simplified in that no adjustment ofthe air doors or distance piece is required throughout the entireoperating range of the burner.

While the instant invention has been disclosed as to particularembodiments thereof, it is to be appreciated that the invention is notto be taken as limited to all of the details thereof, as modificationsand variations thereof may be made without departing from the spirit orscope of the invention.

What is claimed is:

1. For use with a furnace wall having a burner port therein, an improvedgaseous fuel burner comprising an air register for receivingcombustionair at superatrnospheric pressure, said air register having acentral axis, an air inlet, and an axial annular air outlet, adapted tobe concentrically disposed with respect to a burner port, a burnerconduit having a longitudinal axis adapted to connect said annular airoutlet with the burner port and to remotely position said air registerfrom the radiation elfects of the furnace, said burner conduit having adischarge end portion adapted to be disposed immediately adjacent theport, an inner sleeve concentrically disposed within said conduit inspaced relationship therewith, said sleeve having an inlet end openingto said air register for dividing the air leaving said register into aninner air stream and an outer air stream, and said sleeve having anoutlet end spaced along the longitudinal axis of said conduit inwardlyof the discharge end of said burner conduit, means for imparting aturbulent velocity to each of said air streams whereby said streamscreate relative pressure zones within said conduit, and means positionedfor injecting streams of gaseous fuel directly into and transversely ofeach of said air streams within said conduit adjacent theoutlet end ofsaid sleeve so that the relative turbulence and velocity of said airstreams coact to enable the gaseous fuel to be thoroughly mixed withsaid air to enhance combustion, and the relative pressure zonesestablished adjacent the outlet end of said sleeve and the discharge endof said burner conduit creating a flame holding condition thereat.

2. For use with a furnace wall having a burner port therein, an improvedgaseous fuel burner comprising an air register for receiving combustionair at superatmospheric pressure-said air register having a centralaxis, an air inlet, and an axial annular air outlet aadpted to beconcentrically disposed with respect to a burner port, a burner conduithaving a longitudinal axis adapted to connect said annular air outletwith the burner port and to remotely position said air register from theradiation effects of the furnace, said burner conduit having a dischargeend portion adapted to be disposed immediately adjacent the port, saiddischarge end portion having a diameter adapted to be substantiallyequal to the diameter of the burner port, an inner sleeve concentricallydisposed within said conduit in spaced relationship therewith, saidsleeve having an inlet end extending into said air register to permitsaid sleeve to dividethe air in said register into an inner air streamand an outer air stream, and said sleeve having an outlet end spacedalong the longitudinal axis of said conduit inwardly of the dischargeend of said burner conduit, means for imparting a turbulent velocity toreach of said air streams'whereby said streams create relative pressurezones withitn said conduit and gas spuds having opposed, parallel,longitudinally extending wall portions, and a row of spaced orificesdisposed in each of said wall portions, said spuds being positioned sothat the gas streams discharging from said orifices are ejected directlyinto and transversely of each of 'said air streams within said conduitadjacentthe outlet end of said sleeve so that the relative turbulenceand velocity of said air streams co-act to enable the gaseous fuel to bethoroughly mixed with said air to enhance combustion, and the relativepressure zones established adjacent the outlet end of said sleeve andthe discharge end of said burner conduit creating a flame holdingcondition thereat.

3. The invention as defined in claim 2, wherein each of said spudsincludes a tubular member readily detachable from said manifold, each ofsaid members having a tip end, said tip end having an oblique facerelative to an axial plane of said tubular member, said face having aplurality of discharge orifices therein, and said row of aligned spacedorifices positioned on opposite sides of said spuds being disposedadjacent the tip end.

4. For use with a furnace wall having a burner port therein, an improvedimpellerless gaseous fuel burner comprising an air register forreceiving combustion air at superatmospheric pressure, said air registerhaving a central axis, an air inlet, means for imparting a whirlingmotion to the air upon entering said air inlet, and an axial annular airoutlet adapted to be concentrically disposed with respect to the burnerport, a cylindrical burner conduit having a longitudinal axis adapted toconnect said annular air outlet with the burner port and to v remotelyposition said air register from the radiation effects of the furnace,said burner conduit having a smooth inner surface and a discharge endportion adapted to be disposed immediately adjacent the port, saiddischarge end portion having a diameter adapted to be substantiallyequal to the diameter of the burner port, an inner sleeve having asmooth inner surface concentrically disposed within said conduit inspaced relationship therewith, said sleeve having an inlet end extendinginto said air register to divide the whirling air in said register intoa whirling inner air stream and a whirling outer air stream, and saidsleeve having an outlet end spaced along the longitudinal axis of saidconduit inwardly of the discharge end of said burner conduit and thewhirling motion imparted to each of said air streams creating a relativepressure zone within said conduit, and means positioned for injectingstreams of gaseous fuel directly into and transversely of each of saidair streams within said conduit adjacent the outlet end of said sleeveso that the relative whirling movement of said air streams co-act toenable the gaseous fuel to be thoroughly mixed with said air forenhancing combustion, and the relative pressure zones establishedadjacent the outlet end of said sleeve and the discharge end of saidburner conduit creating a flame holding condition thereat.

5. For use with a furnace wall having a burner port therein, an improvedimpellerless gaseous fuel burner comprising an air register forreceiving combustion air at superatmospheric pressure, said air registerhaving a central axis, an air inlet, and an axial annular air outletadapted to be concentrically disposed with respect to the burner port, acylindrical burner conduit having a longitudinal axis adapted to connectsaid annular air outlet with the burner port and to remotely space saidair register from the radiation efiects of the furnace, said burnerconduit having a smooth inner surface and a discharge end portionadapted to be disposed immediately adjacent the port, said discharge endportion having a diameter adapted to be substantially equal to thediameter of the burner port, an inner sleeve having a smooth innersurface concentrically disposed within said conduit in spacedrelationshisp therewith, said sleeve having an inlet end extending intosaid air register to divide the air in said register into an inner airstream and an outer air stream, and said'sleeve having an outlet endspaced along the longitudinal axis of said conduit inwardly of thedischarge end of said burner conduit, adjustable" air register'doors tocontrol the flow of air through said air register inlet, said air doorsimparting a whirling movement to each in said conduit, and meanspositioned for injecting streams of gaseous fuel directly into andtransversely of each of said air streams within said conduit adjacentthe outlet end of said sleeve, said fuel injecting means including a gasmanifold-spaced from the outer side of said air register, and aplurality of circumferentially spaced elongated tubular membersdetachably connected to said manifold, each of said members extendingfrom said manifold to a point adjacent the outlet end of said innersleeve, a tip connected to each of said members, said tips each havingan oblique face relative to an axial plane thereof, said face having aplurality of discharge furnace having a furnace wall with a burneropening therein, a multiple fuel burner capable of a maximum loadcapacity of approximately 183 million B.t.us per hour comprising an airregister for receiving the combustion air, said air register having acentral axis and an annular outlet disposed about said axis, acylindrical conduit having a longitudinal axis and a smooth innersurface connected to said annular outlet for remotely spacing saidregister from a burner port and the radiation effects of the furnace,said conduit having a discharge end portion adapted to be disposedimmediately adjacent a burner port, said discharge end having a diameteradapted to be substantially equal to that of the port, an oil atomizingmeans located along the central axis of the burner, an inner cylindricalsleeve having an inlet end and an outlet end concentrically disposedwithin said conduit and about said atomizing means in spacedrelationship therewith, said inlet end of the sleeve extending into theair register to divide the air in said register into an inner air streamand an outer air stream, and said outlet end 'of said sleeve beingspaced along the longitudinal axis of said conduit inwardly of thedischarge end thereof, a gas burner, said gas burner including a gasmanifold, a plurality of individual gas spuds detachably connected tosaid manifold, said spuds having their tip ends terminating in a circlecircumferentially spaced from the outlet end of said sleeve and withinthe. outer end of said conduit, said spuds having a plurality oforifices positioned to discharge streams of gaseous fuels directly intoand transversely of each of'the said air streams, means impartingrelative velocities to each of said air streams so that the division ofcombustion air by said sleeve facilitates thorough mixing of oil and/orgas with said air and creates a flame holding condition adjacent thedischarge end of the burner conduit whether the said oil or gas is firedseparately or in combination.

7. An improved gaseous fuel burner comprising an air register forreceiving combustion air at superatmospheric pressure, said air registerhaving a central axis, an air inlet, and an annular air outletconcentrically disposed with respectto said central axis, a burnerconduit having a longitudinal axis coincidental with the central axis ofsaid air register, said conduit being adapted for connecting said airregister annular outlet with a burner port and for remotely positioningsaid air register from the radiation effects of a furnace, said burnerconduit having a discharge end portion provided with a diameter adaptedto be substantially equal to the burner port diameter and adapted to bedisposed adjacent a burner port, an inner sleeve concentrically disposedwithin said conduit in spaced relationship therewith, said sleeve havingan inlet end extending into said air register and an outlet end spacedinwardly of the discharge end of said burner conduit along thelongitudinal axis thereof, whereby said inlet end of said sleeve dividesthe air in said air register into an outer air stream and an inner airstream so that the outer air stream is discharged from said air registerthrough said annular outlet and said inner air stream is discharged fromsaid register through said sleeve, means for imparting a turbulentvelocity to each of said air streams for creating relative pressurezones adjacent the discharge end of said conduit, and means positionedfor injecting streams of gaseous fuel directly into and transversely ofeach of said air streams within said conduit adjacent the outlet end ofsaid sleeve so that the relative turbulence and velocity of said airstreams co-act to enable the gaseous fuel to be thoroughly mixed withsaid air to enhance combustion, and the relative pressure zonesestablished adjacent the respective ends of said,

rotating air into an inner and an outer rotating air stream havingrelative angular velocities to create a pair of relative pressure zones,positivelyv directing the inner rotating air stream toward the centralportion of the burner, and injecting streams of gaseous fuel directlyinto and transversely of each of said rotating air streams whereby therotating air streams provide for thorough mixing of the fuel and air toenhance combustion and the relative pressure zones created therebyestablishing a flame holding condition at the burner.

'9. The invention asdefined in claim 1, wherein said means for impartinga turbulent velocity to' said air streams include means for imparting alinear velocity to said outer air stream, and vane means disposed withinsaid air register immediately adjacent the inlet end of said sleeve toinduce a whirling motion to the inner airr stream flowing through saidsleeve.

10. The invention as defined in claim 9, wherein said vane means includea plurality of circumferentially spaced blades defining therebetween aplurality of circumferentially spaced substantially tangential airinlets opening to the inlet end of said inner sleeve.

References Cited inthe file of this patent UNITED STATES PATENTS1,136,849 Tucker Apr. 20, 1915 1,687,390 Ritter Oct. 9, 1928 1,801,431Irish Apr. 21, 1931 1,907,838 Leask May 9, 1933 1,966,524 Schenck Apr.13, 1934 1,986,796 Florez Jan. 8, 1935 2,111,908 Andrews Mar. 22,19382,259,818 Henriksen ,Oct.21, 1941 2,274,818 Zink Mar. 3, 1942 2,359,049Nagel Sept. 26, 1944 2,368,490 Patterson Ian. 30, 1945 2,439,609Mittendorf Apr. 13, 1948 2,485,656 Raskin Oct. 25, 1949 2,515,843 NuylJuly 18, 1950 2,826,249

Poole Mar. 11, 1958

